Pharmaceutical crops - those genetically engineered to produce medicines, vaccines and other pharmaceutical proteins - have been cultivated on a limited scale in California amid increasing U.S. Department of Agriculture regulations to reduce risk of gene flow and contamination of human food and livestock feed, according to a review article published in the April-June 2007 issue of the University of California's peer-reviewed California Agriculture journal. See the entire current issue of California Agriculture at http://californiaagriculture.ucop.edu.

In an eight-page article, Michelle Marvier, associate professor of biology and environmental studies at Santa Clara University, explores the complex scientific, environmental and public policy issues surrounding pharmaceutical crops, and sets forth three frameworks for assessing their risks and benefits.

"Like many new technologies, the genetic engineering of crops to produce pharmaceutical products has great promise. Bananas that could cheaply and easily deliver vaccines throughout the tropics could be a wonderful invention," Marvier wrote. "But there are downsides; it will be difficult to avoid food contamination and potential harmful effects to wildlife if pharmaceuticals are widely produced in food crops grown out of doors."

Eighteen federal permits were issued between 1996 and March 2007 for field trials in California involving pharmaceutical or industrial proteins. Some of these approved permits were for field trials of Ventria Bioscience's rice, engineered to express human genes with medicinal properties. These field trials were opposed by rice growers concerned about the possible contamination of rice destined for export, and Ventria has since moved its production of pharmaceutical rice out of California.

Also in the current issue, University of California researchers report on the emergence of glyphosate (Roundup)-resistant horseweed in noncrop areas of California. While the authors did not determine the source of horseweed resistance in these areas, there have been numerous reports of Roundup-resistant weeds occurring near row crops such as corn and soybeans that have been genetically engineered to be resistant to the herbicide glyphosate.

These two articles continue a California Agriculture series on the risks and benefits of agricultural biotechnology, which began with peer-reviewed articles on gene flow, and transgenic animals and fish in the July-September 2006 issue: http://californiaagriculture.ucop.edu/0603JAS/toc.html.

Read the entire current issue of California Agriculture: http://californiaagriculture.ucop.edu

California Agriculture is the University of California's peer-reviewed journal of research in agricultural, human and natural resources. For a free subscription, go to: http://californiaagriculture.ucop.edu, write to calag@ucop.edu or call (510) 987-0044. For a printed copy of California Agriculture, media should e-mail janet.byron@ucop.edu or call (510) 987-0668.